add interface for popularity statistics

moves popularity statistics functionality into pluginrepo
https://bugs.dokuwiki.org/index.php?do=details&task_id=2831

  * reordered helper components
  * rebuild old statistics interface.
  * add line and pie charts support
  * allow selecting data in curtain time interval
  * more..

 * [x] in curtain time interval, the overall submits equal to 100%, and not these in the interval. So update max count as well.
 * [ ] Bad performance of joins